Communication system

Abstract

A communication system is disclosed in which a base station communicates with machine-type-communication (MTC) devices by dividing the base station's cell bandwidth into (non-overlapping) narrowbands and subframes in each narrowband. The base station generates and transmits control information (DCI) for allocating a set of physical resource blocks (PRBs) in a plurality of subframes for an MTC device. After the base station transmits the data, the MTC device generates and transmits an HARQ feedback indicating that i) the data has been successfully received in each one of the plurality of subframes (e.g. a single ‘ACK’) or ii) the data has not been received in at least one of the plurality of subframes (e.g. a single ‘NACK’).

The invention claimed is: 
     
       1. A method performed by a base station, the method comprising:
 transmitting, to a mobile terminal, downlink control information (DCI) for assigning communication resources in at least one subframe for transmitting data, wherein the DCI includes information indicating a number of transport blocks in the at least one subframe; 
 transmitting, to the mobile terminal, the data using the communication resources; and 
 receiving, from the mobile terminal, bundled information of Hybrid Automatic Repeat Request (HARQ)-Acknowledgement (ACK) feedback for acknowledging receipt of the data by the mobile terminal, 
 wherein, in a case where transport blocks are received, by the mobile terminal, for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes an ACK, and in a case where transport blocks are not received, by the mobile terminal, for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes a negative ACK (NACK). 
 
     
     
       2. The method according to  claim 1 , wherein
 the DCI includes information indicating a predetermined number of subframes following a last subframe of subframes in which the transport blocks are received by the mobile terminal, and 
 the bundled information of HARQ-ACK feedback is transmitted in a subframe indicated by the information. 
 
     
     
       3. A method performed by a mobile terminal, the method comprising:
 receiving, from a base station, downlink control information (DCI) for assigning communication resources in at least one subframe for receiving data, wherein the DCI includes information indicating a number of transport blocks in the at least one subframe; 
 receiving, from the base station, the data using the communication resources; and 
 transmitting, to the base station, bundled information of Hybrid Automatic Repeat Request (HARQ)-Acknowledgement (ACK) feedback for acknowledging receipt of the data by the mobile terminal, 
 wherein, in a case where transport blocks are received for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes an ACK, and in a case where transport blocks are not received, by the mobile terminal, for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes a negative ACK (NACK). 
 
     
     
       4. The method according to  claim 3 , wherein
 the DCI includes information indicating a predetermined number of subframes following a last subframe of subframes in which the transport blocks are received by the mobile terminal, and 
 the bundled information of HARQ-ACK feedback is transmitted in a subframe indicated by the information. 
 
     
     
       5. A base station comprising:
 at least one memory storing instructions; and 
 at least one processor configured to process the instructions to:
 transmit, to a mobile terminal, downlink control information (DCI) for assigning communication resources in at least one subframe for transmitting data, wherein the DCI includes information indicating a number of transport blocks in the at least one subframe, 
 transmit, to the mobile terminal, the data using the communication resources, and 
 receive, from the mobile terminal, bundled information of Hybrid Automatic Repeat Request (HARQ)-Acknowledgement (ACK) feedback for acknowledging receipt of the data by mobile terminal, 
 
 wherein, in a case where transport blocks are received, by the mobile terminal, for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes an ACK, and in a case where transport blocks are not received, by the mobile terminal, for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes a negative ACK (NACK). 
 
     
     
       6. A mobile terminal comprising:
 at least one memory storing instructions; and 
 at least one processor configured to process the instructions to: 
 receive, from a base station, downlink control information (DCI) for assigning communication resources in at least one subframe for receiving data, wherein the DCI includes information indicating a number of transport blocks in the at least one subframe,
 receive, from the base station, the data using the communication resources, and 
 transmit, to the base station, bundled information of Hybrid Automatic Repeat Request (HARD)-Acknowledgement (ACK) feedback for acknowledging receipt of the data by the mobile terminal, 
 wherein, in a case where transport blocks are received for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes an ACK, and in a case where transport blocks are not received for the number of transport blocks indicated by the DCI, the bundled information of HARQ-ACK feedback includes a negative ACK (NACK).